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Contract No. DE-AC36-08GO28308

EERE Quality Control Workshop 

Final Report

Proceedings from the EERE Quality Control 

Workshop, in support of the DOE Clean Energy 

Manufacturing Initiative

Golden, Colorado

December 9–10, 2013

Workshop Proceedings

NREL/BK-5900-61889

May 2014
NREL is a national laboratory of the U.S. Department of Energy

Office of Energy Efficiency & Renewable Energy

Operated by the Alliance for Sustainable Energy, LLC

This report is available at no cost from the National Renewable Energy

Laboratory (NREL) at www.nrel.gov/publications.

Contract No. DE-AC36-08GO28308

National Renewable Energy Laboratory

15013 Denver West Parkway

Golden, CO 80401

303-275-3000 • www.nrel.gov

EERE Quality Control 

Workshop Final Report

Proceedings from the EERE Quality Control 

Workshop, in support of the DOE Clean Energy 

Manufacturing Initiative

Golden, Colorado

December 9–10, 2013

NREL Contact: Michael Ulsh

Prepared under Task No. BE4C.SC01

Workshop Proceedings

NREL/BK-5900-61889

May 2014
NOTICE

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iii

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EERE Quality Control Workshop

Workshop held December 9–10, 2013 

National Renewable Energy Laboratory, Energy Systems Integration Facility

15013 Denver West Parkway 

Golden, CO 80401 

Co-Sponsored By: 

U.S. Department of Energy—Fuel Cell Technologies Office (FCTO), Solar Energy Technologies 

Office (SETO), Vehicle Technologies Office (VTO), Building Technologies Office (BTO), and 

Advanced Manufacturing Office (AMO)

Organized and Hosted By: 

National Renewable Energy Laboratory (NREL)

Lead Organizers:

Nancy Garland, FCTO 

Michael Ulsh, NREL

Organizing Committee:

Nancy Garland, FCTO 

Cassidy Houchins, SRA 

Devanand Shenoy, AMO 

Joe Cresko, AMO

David Hardy, AMO 

Peter Faguy, VTO

Antonio Bouza, BTO 

Shubhra Bansal, SETO

Michael Bolen, SETO

Jesse Adams, FCTO

Michael Ulsh, NREL

Breakout Group Facilitators: 

Michael Bolen, SETO

Nancy Garland, FCTO 

Peter Faguy, VTO

Antonio Bouza, BTO 

Michael Ulsh, NREL

Claus Daniel, Oak Ridge National Laboratory 

Jesse Adams, FCTO

Breakout Group Scribes: 

Kim Cierpik, CAS-Navarro Joint Venture, LLC 

Cassidy Houchins, SRA 

Nathan Moore, CAS-Navarro Joint Venture, LLC 

Stephanie Hodge, CAS-Navarro Joint Venture, LLC 

Shaun Onorato, CAS-Navarro Joint Venture, LLC 
iv

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Executive Summary

The U.S. manufacturing sector accounts for about 12% of the nation’s gross domestic product, 

70% of domestic industrial research and development spending, and 86% of all U.S. export 

goods. It employs 60% of industry’s scientists and engineers. Each of these jobs, on average, 

supports 2.5 jobs in other sectors and, for high-tech manufacturing jobs, up to 16 other jobs are 

supported. Similarly, every dollar of manufactured goods sales supports $1.35 in output from 

other sectors—the highest “multiplier” of any sector of the economy. 

In response to this importance, and in the face of ever increasing global competition for U.S. 

manufacturers, the U.S. government has initiated a whole-of-government Advanced 

Manufacturing Initiative to enable manufacturing innovation, secure America’s talent pipeline, 

and improve the business climate for manufacturing. Among the cross-cutting technologies seen 

as critical to enable manufacturing innovation is a family of disciplines including advanced 

sensing and measurement, process control and feedback, and information technology for 

manufacturing. The need for sensing, data gathering and analysis, and integration of 

manufacturing data for high quality, efficiency, and resource optimization is especially great for 

clean energy technologies, many of which are characterized by low market volumes and are 

being developed by small and medium sized enterprises often not having the corporate 

competencies to adequately address process scale-up and the associated quality inspection and 

control issues.

Within this backdrop, the U.S. Department of Energy (DOE) Office of Energy Efficiency and 

Renewable Energy (EERE) has recognized the cross-cutting, pre-competitive, and enabling 

nature of quality control (QC) for a wide range of clean energy technologies. As such, the Fuel 

Cell Technologies Office, Solar Energy Technologies Office, Vehicle Technologies Office, and 

Building Technologies Office, as well EERE’s Advanced Manufacturing Office and Clean 

Energy Manufacturing Initiative, decided to explore needs and potential cross-office synergies in 

this area by holding a workshop. The purpose of the workshop was to convene government, 

industry, and other stakeholders to discuss the current status of quality control and metrology in 

manufacturing processes relevant to the EERE offices, note gaps in which current techniques are 

inadequate or missing altogether, discuss similarities in materials inspection and metrology needs 

across technologies, and identify opportunities for collaboration across EERE offices to address 

shared challenges.

The scope of the workshop was determined to be quality control at the part and/or sub-assembly 

level during manufacturing, specifically for materials in the form of sheets or characterized by 

two-dimensional surfaces. This topic was selected in part because many of the existing activities 

supported by these offices to address quality control relate to these kinds of materials. Because 

these materials are often produced using continuous processes (e.g., roll-to-roll or belt-fed 

processes), “in-line” inspection—or techniques that can be used directly on the manufacturing 

line while the material is being produced, and thus are typically rapid, non-contact, and nondestructive in nature—was of highest interest. The workshop was held at the National Renewable 

Energy Laboratory’s Energy Systems Integration Facility in Golden, Colorado, on December 9 

and 10, 2013. 
v 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

The structure of the workshop was designed to (a) establish a common baseline, in terms of 

processes, materials, and quality control techniques and (b) facilitate open and collaborative 

discussion to identify potential synergies, remaining needs, and key recommendations. These 

two requirements were important to enable easy and fruitful interaction between the participants, 

who represented a broad range of technologies. The key information-gathering element of the 

workshop was a series of three breakout sessions. The first session was a review of quality 

control challenges across the four technology offices. The second was a discussion of potential 

synergies across offices and quality control techniques. And the third was a discussion of key 

quality control needs that are not currently being addressed, and final recommendations. 

Forty participants from industry, labs, and DOE, representing a wide range of clean energy 

technologies, provided their thoughts and experiences about QC challenges and contributed their 

ideas and suggestions about potential synergistic activities and how to move forward 

collaboratively in addressing these challenges. The outputs of the workshop logically lent 

themselves to categorization into conclusions and recommendations, the former taking the form 

of specific technical topics to be addressed and the latter as proposed activities for EERE and 

industry to pursue.

Three broad technical topics were identified for further action. 

1. Cross-cutting QC development needs, including: 

a. Thickness measurement

b. Inspection for mechanical defects such as pinholes and cracks

c. Measurement of electrical properties

d. Measurement of surface texture, structure, and morphology 

e. Inspection for inter-layer delamination and voids 

f. Improving the sensitivity of sensors 

g. Advancing tools and methods for QC data collection, analysis, storage, and use. 

2. Correlation of defects to cell or device performance and lifetime, including: 

a. Methods for differentiating between fatal defects and process drift

b. Process control for defect reduction 

c. Defect marking, removal, and/or correction. 

3. Development of analyses to define and communicate the costs and benefits of in-line QC 

as a function of material requirements and manufacturing processes, yields, volumes, and 

costs.

In addition, two key programmatic areas were identified to assist industry, labs, and DOE in 

moving forward with cross-office, collaborative efforts to address these technical areas. 

1. Methods to improve communications and interactions with and technology transfer to 

industry, including:

a. Holding webinars and posting case studies on the Web
vi 

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b. Connecting with other U.S. government entities that may have established best 

practices for interaction with industry on manufacturing topics 

c. Supporting continued inclusion of QC-related topics in funding opportunities and 

Small Business Innovation Research (SBIR) calls

d. Developing and making available a catalog of QC techniques, their capabilities, 

applications, and suppliers/developers. 

2. Facilitation of more detailed technical exchange between researchers, developers, and 

vendors across the different technology areas to better identify synergies, including: 

a. Convening technical meetings to enable detailed understanding of techniques, 

capabilities, equipment, and methods, possibly co-located with relevant 

conferences or DOE program reviews 

b. Developing improved methods to enable, fund, and reward cross-office 

collaborations between lab researchers within the Annual Operating Plan process.
vii 

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Table of Contents

List of Figures .......................................................................................................................................... viii

List of Tables ............................................................................................................................................ viii

Introduction ................................................................................................................................................. 1

Background and Motivation................................................................................................................... 1

Workshop Description............................................................................................................................ 3

Current Status / State-of-the-Art for In-Line QC....................................................................................... 6

Overview of Relevant Processes............................................................................................................ 6

Overview of Lithium Ion Electrode QC Development Activities at Oak Ridge.................................... 9

Overview of Quality Control Techniques ............................................................................................ 10

Status of EERE Activities .................................................................................................................... 13

Preliminary Industry Inputs.................................................................................................................. 15

Industry Panel Session.......................................................................................................................... 16

Summary and Key Learnings from the Breakout Sessions ................................................................. 19

Breakout 1: QC Challenges.................................................................................................................. 19

Breakout 2: Synergies .......................................................................................................................... 21

Breakout 3: Remaining R&D Needs and Recommendations............................................................... 24

Conclusions and Recommendations...................................................................................................... 28

Conclusions.......................................................................................................................................... 28

Recommendations................................................................................................................................ 29

References................................................................................................................................................. 31

Appendix A. Workshop Agenda .............................................................................................................. 32

Appendix B. List of Attendees................................................................................................................. 33

Appendix C. Detailed Notes From Breakout Sessions ........................................................................ 34

Breakout 1: QC Challenges.................................................................................................................. 34

Breakout 2: Synergies .......................................................................................................................... 37

Breakout 3: Remaining R&D Needs and Recommendations............................................................... 40
viii

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List of Figures

Figure 1. Workshop scope ......................................................................................................................... 4

Figure 2. Roll-to-roll line. Photo by Michael Ulsh, NREL ........................................................................ 7

Figure 3. (Left) screen printing and (right) tape casting. Photos from M. Richards, Versa Power 

Systems................................................................................................................................................. 8

Figure 4. Reel-to-reel vacuum deposition line. Photo from Global Solar Energy, NREL 13414 ......... 9

Figure 5. Thickness measurement of lithium manganese cathode using a Keyence dual laser 

system ................................................................................................................................................. 10

Figure 6. Optical reflectance measurement of silicon wafer grain boundaries.................................. 12

Figure 7. Thermal signature of fuel cell electrode with a void using electrical excitation and IR CCD 

detector................................................................................................................................................ 13

List of Tables

Table 1. Summary of EERE Activities..................................................................................................... 13

Table 2. Industry Responses to Questionnaire...................................................................................... 15

Table 3. Industry Panel Discussion Session.......................................................................................... 16

Table 4. Summary of Key Points from Moderated Panel Session ....................................................... 17

Table 5. Summary of Audience Q&A Session with Panelists............................................................... 18

Table 6. Objective and Discussion Questions for Breakout Session 1: QC Challenges................... 19

Table 7. Summary Responses from Breakout Session 1 by Technology Group............................... 20

Table 8. Objective and Discussion Questions for Breakout Session 2: Synergies ........................... 22

Table 9. Summary Responses from Breakout Session 2 by Group .................................................... 23

Table 10. Objective and Discussion Questions for Breakout Session 3: Remaining R&D Needs and 

Recommendations ............................................................................................................................. 24

Table 11. Summary Responses from Breakout Session 3 by Group .................................................. 25

Table C-1. Notes from Breakout 1A—SETO ........................................................................................... 34

Table C-2. Notes from Breakout 1B—FCTO ........................................................................................... 35

Table C-3. Notes from Breakout 1C—VTO.............................................................................................. 36

Table C-4. Notes from Breakout 1D—BTO ............................................................................................. 37

Table C-5. Notes from Breakout 2A......................................................................................................... 37

Table C-6. Notes from Breakout 2B......................................................................................................... 39

Table C-7. Notes from Breakout 2C......................................................................................................... 40

Table C-8. Notes from Breakout 3A......................................................................................................... 40

Table C-9. Notes from Breakout 3B......................................................................................................... 42

Table C-10. Notes from Breakout 3C....................................................................................................... 43
1 

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Introduction

Background and Motivation

American manufacturing, and the competitiveness of this sector of the U.S. economy, has been a 

topic of extensive and growing discussion in economic, technical, and political spheres over the 

past few years. Indeed, while the U.S. manufacturing sector has shed millions of jobs since the 

late 1970s [1], it remains a critical driver of the American economy. Manufacturing provides 

about 12% of the nation’s gross domestic product. It accounts for 70% of domestic industrial 

research and development (R&D) spending and 86% of all U.S. export goods, and it employs 

60% of industry’s scientists and engineers [2, 3]. Furthermore, manufacturing jobs and economic 

output have a strong impact on the rest of the economy. On average, each manufacturing job 

supports 2.5 jobs in other sectors; for high-tech manufacturing jobs, up to 16 other jobs are 

supported. Similarly, every dollar of manufactured goods sales supports $1.35 in output from 

other sectors—the highest “multiplier” of any sector of the economy [1]. The strength of the 

American manufacturing sector is also critical to national security. According to the 2010 

Quadrennial Defense Review [4], “In the mid to long term, it is imperative that we have a robust 

industrial base with sufficient manufacturing capability and capacity to preserve our 

technological edge and provide for the reset and recapitalization of our force.” 

With this importance in mind, several studies 

by the Executive Office of the President [1, 3, 

5] have called for a national strategy for 

advanced manufacturing and the creation of a 

“whole-of-government” Advanced 

Manufacturing Initiative (AMI). The wholeof-government effort officially began on June 

24, 2011, with the announcement by 

President Obama of the Advanced 

Manufacturing Partnership [6], a 

collaboration between industry and several 

government agencies including the U.S. 

Department of Energy (DOE), with a stated 

mission to “Identify opportunities for 

investments in R&D, pre-competitive 

collaboration, and shared facilities and 

infrastructure that have the potential to 

transform advanced manufacturing in the United States, and recommend collaborative 

approaches that will realize these opportunities.”

The AMI is to be framed by the three pillars of: (i) enabling manufacturing innovation, (ii) 

securing America’s talent pipeline, and (iii) improving the business climate for manufacturing 

[1]. Within the first pillar, a strong emphasis was placed on cross-cutting technologies that are 

vital to advanced manufacturing. The need for cross-cutting investments was echoed by the 

National Science and Technology Council, which described efforts that are “beyond the purview 

of any one agency or private-sector entity, but are collectively viewed as critical to advancing 

President’s Council of Advisors on 

Science and Technology definition of 

advanced manufacturing [3]: 

“a family of activities that (a) depend on the 

use and coordination of information, 

automation, computation, software, sensing, 

and networking, and/or (b) make use of 

cutting edge materials and emerging 

capabilities enabled by the physical and 

biological sciences, for example 

nanotechnology, chemistry and biology. This 

involves both new ways to manufacture 

existing products, and especially the 

manufacture of new products emerging from 

new advanced technologies.” 
2 

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key national interests” and “should be used to strengthen the industrial commons in a way that 

would benefit all the participating agencies (and their stakeholders)” [5]. 

The President’s Council of Advisors on Science and Technology further defines a list of “Top 

Cross-Cutting Technologies” that spans a spectrum from process technologies to enabling 

technologies to sustainable business practices [1]. Several of the categories, including 

“Advanced Sensing, Measurement, and Process Control,” “Visualization, Informatics, and 

Digital Manufacturing Technologies,” “Sustainable Manufacturing,” and “Advanced 

Manufacturing and Testing Equipment,” highlight the criticality of capturing and utilizing data 

during the manufacture of advanced products. The group describes as a key national need 

“technologies and systems that enable optimal raw material, energy, and resource utilization,” 

and states that “megatrends of energy and resource efficiency, better safety, and higher quality 

also depend highly on advances in sensing and automatic process control.” In a similarly-focused 

study, the Massachusetts Institute of Technology (MIT) assessed the importance of production in 

our innovation economy [7, 8] by surveying large universities on the importance of a set of 

manufacturing-based technologies or technology needs. Highly rated categories included 

“Advanced Sensing,” “Information Tech for Manufacturing,” “Continuous Process Control,” and 

“Advanced Metrology”. 

The need for sensing, data gathering and analysis, and integration of manufacturing data for high 

quality, efficiency, and resource optimization is especially great for clean energy technologies. 

As stated by DOE’s Advanced Manufacturing Office (AMO) in the introduction to their 

Membrane Technology Workshop Report [9], “New membrane materials, developed at 

laboratory scale, offer significant benefits over currently available commercial membranes. 

However, manufacturing defects and high module costs at full production scale are preventing 

widespread adoption in applications where membranes hold the greatest promise to reduce 

energy consumption and manufacturing costs.” 

This assessment is indicative of many clean energy technologies and has motivated several DOE 

Office of Energy Efficiency and Renewable Energy (EERE) technology offices, including the 

Fuel Cell Technologies Office (FCTO), Solar Energy Technologies Office (SETO), and Building 

Technologies Office (BTO), to hold similar workshops wherein quality control (QC) and 

inspection needs are discussed concurrently with material and process development needs [10,

11, 12]. In the case of FCTO, these learnings for hydrogen and fuel cell technologies have been 

included in updates to multi-year program plans in the form of specific tasks and milestones [13]. 

Similarly, in their review of critical manufacturing R&D needs in three key technology areas—

hydrogen technologies, nanomanufacturing, and intelligent and integrated manufacturing—the 

National Science and Technology Council points out the need for “ensuring near-zero defect 

standards in manufacturing.” In specific examples, the group lists the need to develop in-line 

quality control methods concurrent with development of advanced processes for fuel cell 

membrane fabrication and catalyst layer deposition and instrumentation and metrology for 

nanomanufacturing processes, where thin-film and nanoscale production—relevant to many 

clean energy technologies such as photovoltaics (PV)—will present particular challenges [14]. 

Another reason this area of quality inspection is important for clean energy technologies, as 

discussed generally in MIT’s report on production and innovation [8], is that many of the 

companies working to develop these technologies are small and medium sized enterprises that do 
3 

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not have the corporate bandwidth and competencies to adequately address process scale-up and 

the associated quality inspection and control issues. 

Workshop Description

Within this backdrop, several EERE technology offices, as well as AMO and EERE’s Clean 

Energy Manufacturing Initiative (CEMI), have recognized the cross-cutting, pre-competitive, 

and enabling nature of quality control for a wide range of clean energy technologies. 

Furthermore, there was a realization that many components and assemblies of interest to these 

offices are of similar format and that inspection and metrology solutions available or in 

development for one product may be applied, perhaps with minor modification, to other products 

of similar format. As a result, these offices and activities decided to explore QC needs and 

potential cross-office synergies by holding a workshop. The purpose of the workshop was to 

convene government, industry, and other stakeholders to discuss the current status of quality 

control/quality assurance and metrology in manufacturing processes relevant to the EERE 

offices; note gaps in which current diagnostic techniques are inadequate or missing altogether; 

discuss similarities in materials inspection and metrology needs across technologies; and identify 

opportunities for collaboration across EERE offices to address shared challenges. The results of 

the workshop are expected to inform EERE of opportunities to address synergistic and crosscutting measurement and inspection needs for EERE technologies, leading to accelerated 

collaboration with and transfer of these technologies to industry. 

The Clean Energy Manufacturing 

Initiative is an integration of 

manufacturing efforts across all offices 

of EERE to advance (a) the production 

of competitive clean energy 

technologies and (b) activities and 

technologies that strengthen 

competitiveness across multiple 

manufacturing industries through 

increased energy productivity [15]. 

Photo from the Clean Energy 

Manufacturing Initiative launch on

March 26, 2013 at the opening of the 

Carbon Fiber Technology Facility, part 

of the DOE Manufacturing 

Demonstration Facility at ORNL

Clean Energy Manufacturing Initiative
4 

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A key initial task for the workshop planning team, which comprised members from FCTO, 

SETO, the Vehicle Technologies Office (VTO), BTO, AMO, and the National Renewable 

Energy Laboratory (NREL), was to establish the scope of the workshop within the technically 

broad topic of quality control. Generically, the team characterized quality needs across the 

spectrum of the manufacturing enterprise as shown in Figure 1. Important quality requirements 

exist across several categorizations of manufacturing activities, from quality assurance of 

incoming lots of raw materials to final testing of the operational performance of a system or 

assembly in the factory and at the point of use. However, the focus for this workshop was quality 

control at the part and/or sub-assembly level during manufacturing. At a lower level, the team 

identified three categorizations of products or materials of interest to these EERE offices that 

could require very different inspection and metrology capabilities: materials in the form of sheets 

or characterized by two-dimensional (2D) surfaces, piece parts or three-dimensional (3D) 

structures, and liquids. The team selected the first of these categories as the topic for the 

workshop—in part because many of the existing activities supported by these offices to address 

quality control relate to these kinds of materials—although a strong desire for follow-on 

workshops to address the other two areas was clearly noted. Because this first category of 

materials is often produced using continuous processes (e.g., roll-to-roll or belt-fed processes), 

“in-line” inspection—or techniques that can be used directly on the manufacturing line while the 

material is being produced, and thus are typically rapid, non-contact, and non-destructive in 

nature—is often of highest interest. 

Figure 1. Workshop scope
5 

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The workshop was held at NREL’s Energy Systems Integration Facility in Golden, Colorado, on 

December 9 and 10, 2013. The structure of the workshop was designed to (a) establish a 

common baseline, in terms of processes, materials, and quality control techniques and (b) 

facilitate open and collaborative discussion to identify potential synergies, remaining needs, and 

key recommendations. These two requirements were important to enable easy and fruitful 

interaction between the participants, who represented a broad range of technologies. The 

following format was used: 

• Welcome statements from NREL, FCTO, and AMO

• Overview presentations on relevant materials, processes, and quality control techniques

• An industry panel discussion on manufacturing quality control 

• A summary presentation on current activities and in-line quality control needs and 

challenges previously identified by the participating offices

• Three breakout sessions 

o Breakout 1: A review of quality control challenges (four sessions were held, one 

for each of the technology offices) 

o Breakout 2: A discussion of potential synergies across offices and quality control 

techniques (three identical sessions were held, with mixed groupings of 

participants from across all technologies)

o Breakout 3: A discussion of key quality control needs that are not currently 

available or being addressed, and final recommendations (again, three identical 

sessions were held, with mixed groupings of participants from across all 

technologies) 

• A summary and wrap-up. 

Tours of several NREL laboratories with ongoing research in quality control technique 

development were also held. 

The final workshop agenda is given in Appendix A. Forty participants from DOE, industry, labs, 

and academia were present, as listed in Appendix B. Finally, detailed notes from each of the 

breakout sessions are given in Appendix C. 
6 

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Current Status / State-of-the-Art for In-Line QC

As noted previously, similarities in the format and structure of materials across the different 

EERE offices were the main motivation for this workshop. Silicon wafers, battery electrodes, 

fuel cell membranes, and electrochromic window films are just a few examples of materials that 

are characterized by a two-dimensional functional surface, often with one or more coated or 

deposited layers. Not surprisingly, these materials are often made using similar processes—

namely continuous roll-to-roll, belt-fed, or conveyor-based processes that enable successive steps 

to build a final construction at high throughput. While these processes are typically desirable 

from a cost-per-unit-area point of view, they make quality control difficult because 

measurements must be made while the material is moving and potentially under process line 

conditions (e.g., temperature, humidity, pressure, and non-air gas environments) that may be 

challenging for certain measurement techniques. 

Overview presentations were given to facilitate a common basis of understanding of the 

processes and quality control techniques in use and potentially of interest for this workshop. To 

further orient the participants, a summary of recent and ongoing EERE-sponsored quality 

measurement and inspection development activities relevant to these materials and processes was 

given. In addition, in recognition of the very important role that industry participant input would 

play in the success of the workshop, a panel discussion was held with panel members whose 

experience spanned several of the technologies of interest to the participating EERE offices. 

Summaries of these presentations and discussions are given in the following sections. 

Overview of Relevant Processes

This overview by Michael Ulsh of NREL was broken down into two sections: a review of types 

of continuous production machinery, or “lines”, that these materials are typically fabricated on, 

and a review of the general process types that are employed on these lines to create the twodimensional, often multi-layer surfaces of interest.

Example battery electrode (left) and thin film (right) materials. Photos from David 

Wood, Oak Ridge National Laboratory (L) and Warren Gretz, NREL 03541 (R)
7 

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Continuous sheet-based lines take several forms. Roll-to-roll lines are used when a flexible 

continuous sheet, or “web”, can be conveyed on the line as exemplified in Figure 2. In addition 

to the web speed, the tension of the web is typically controlled to ensure that the motion of the 

web across and around a multiplicity of rollers is done in a way that does not cause stretching or 

wrinkling of the web. Belt-fed lines are similar and are used when support of the web during 

processing is required, for example during high-temperature process steps, or when sheet 

materials are not flexible enough to feed around rollers. Float lines are similar in concept and 

allow long sheets of material such as glass to be processed while moving and supported on a 

liquid surface. Finally, conveyors are used for cases such as silicon photovoltaic wafers wherein 

discrete parts are processed in a continuous fashion. 

Figure 2. Roll-to-roll line. Photo by Michael Ulsh, NREL

Many different permutations of processes are used on these continuous lines—too many to 

review in detail. Instead, broad categories of processes were highlighted. Most of the materials of 

interest for the workshop involve some kind of coating or deposition—often several in series—to 

create functional layers and surfaces. These additive processes are categorized by the pressure at 

which the coating is applied: either at atmospheric (room) pressure or in a vacuum. Atmospheric 

coatings take several generic forms. Roll coating is characterized by two or more rollers, in a 

wide variety of configurations, being used to “pick up” a thin layer of liquid from a bath and 

apply it to a surface of a web. Knife coating is similar to roll coating, wherein a stationary bar or 

rod—the “knife”—is set to a certain stand-off distance from the web and is used to control the 

amount of liquid deposited onto the web from a reservoir. Various masks or other limits to the 

location or position of the coated liquid can be employed, as in screen printing. Two industry 

examples of knife-based techniques are shown in Figure 3. Die coating is the generic term for a 

wide variety of techniques characterized by a sheet of coating being dropped or laid onto the 

web. The die comprises two or more typically metal plates with machined flowfields between to 

enable the creation of a highly uniform sheet of coating. And finally, for the atmospheric 

coatings, spray methods are often employed using a spray head, or an array of spray heads, to 

coat the web from side to side. Low-temperature systems are used most often, including a variety 
8 

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of jet methods as well as systems where the head is ultrasonically actuated to break up droplets 

and particles into a very fine spray. In cases where the substrate or base material can withstand 

the thermal load, high-temperature sprays can be used, including electrical arc and plasma-based 

methods. In almost all cases of liquid coatings applied under atmospheric pressure, some kind of 

drying and/or curing of the coating is required. Drying is used to drive off solvents that are used 

to make a coat-able mixture but are not desired in the final layer, and it is typically accomplished 

using heated gas or infrared heat sources. Curing is a post-treatment process to finalize the 

chemical or morphological nature of the coating by irradiation with an energy source such as 

infrared or ultraviolet lamps, or an electron beam. 

Figure 3. (Left) screen printing and (right) tape casting. Photos from M. Richards, Versa Power 

Systems

Vacuum coating techniques also come in a wide variety of types, including sputtering, many 

different kinds of vapor deposition processes, and evaporative coating. These processes are 

typically used for very thin coatings—usually less than a micrometer in thickness. Importantly, 

when vacuum processes are used in continuous production, complicated and expensive line 

equipment must be employed to allow movement of the web while still maintaining very low 

pressure. An example of this highly specialized type of equipment is shown in Figure 4. 

Especially in the case of silicon photovoltaics, several mechanical processing steps are also used, 

including cutting or sawing processes, texturing of the surface, and creation of electrical 

junctions. 
9 

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Figure 4. Reel-to-reel vacuum deposition line. Photo from Global Solar Energy, NREL 13414

Overview of Lithium Ion Electrode QC Development Activities at Oak 

Ridge

As a specific example of DOE-supported work on the development and validation of QC 

techniques for clean energy technologies, David Wood of Oak Ridge National Laboratory gave a 

presentation describing the state-of-the-art of production quality control for lithium ion battery 

electrodes. For in-line measurements, beta transmission gauges are commonly used to measure 

thickness and/or areal weight of the coating, and optical charge-coupled device (CCD) cameras 

are used for visible defects. The greatest needs for lithium ion electrode QC were given as 

pass/fail criteria for electrodes, correlation of defects with cell performance and capacity fade, 

and implementation of feedback loops from coating to deposition. X-ray fluorescence (XRF) for 

compositional analysis and optical microscopy for surface structure were described as techniques 

currently being employed off-line. A focus of the work at Oak Ridge National Laboratory 

(ORNL), which is sponsored by VTO, is to identify and develop techniques that cost less and are 

more easily implementable on production lines. To this end, laser-based thickness measurement 

and infrared (IR) thermography-based detection of defects is being demonstrated. Other activities 

being pursued included acoustic agglomerate-size measurement of electrode dispersions, IRbased thermal diffusivity measurement of electrode coatings to determine porosity, XRF 

techniques with improved accuracy and speed of measurement, and spectrophotometric analysis 

for thickness and areal weight uniformity. Highlights of these developments were given, 

including laser-based thickness measurement, as shown in Figure 5 for a wet lithium-manganeserich cathode, where Δd/d represents a normalized thickness value. 
10 

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Figure 5. Thickness measurement of lithium manganese cathode using a Keyence dual laser 

system

Overview of Quality Control Techniques

As previously discussed, the materials of interest for this workshop are characterized by a 

functional surface created by one or more thin layers. Given that functionality is usually related 

to quantity, the thickness of the layers is usually very important. Beyond this, however, a wide 

range of measurements could be of interest, depending on the composition and functionality of 

the material. These measurements can be made with either single-point or multiple-point 

detectors. As a complicating factor, non-uniformity of these layers—resulting from a myriad of 

possible sources—often is not detected by single-point measurements. In a third presentation, 

Michael Ulsh of NREL reviewed schemes for enabling the required measurements given the 

above considerations, different types of measurements of interest, and examples of point, line, 

and areal detectors and techniques currently used or of interest.

Beyond thickness, various dimensional measurements may be of interest. Measurement of the 

coated width of the material is often of interest for controlling scrap and ensuring materials are 

made to specification. Alternately, if the coating does not cover the entire surface of the substrate 

material, the distance from the edge of the coating to the edge of the substrate is often of interest. 

In cases of multiple layers, especially when patterned or patch coatings are employed—using 

screen printing or other masking methods—the registration or alignment of one layer on top of 

the previous layer is often very important. For example, misalignment of a fuel cell electrode on 

top of an ion-conducting membrane can reduce performance and lead to accelerated degradation. 
11 

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In addition to dimensional measurements, 

functional measurements—or measurements of 

material properties—are often of interest. 

Chemical composition and mechanical, 

electrical, and optical properties may all be 

important to understand in-line, both from the 

perspective of process control as well as for 

proper functionality of the material. Catalyst 

content of electrodes, wafer grain boundaries, 

hydrophobic additive content in fuel cell gas 

diffusion media, in-plane and through-plane 

conductance, and the reflectance of a textured 

wafer surface all are examples of functional or 

property measurements.

Finally, identifying non-uniformities is almost always extremely critical for proper performance 

of these materials. Non-uniformities can come in many forms and result from many sources. 

Some non-uniformities can be surface effects—for example due to improper drying conditions—

that cover all or large sections of a surface. They can be linear in the direction of motion of the 

web, for example lines of reduced thickness caused by a particle caught in a die. Or, they can be 

randomly dispersed discrete or point defects, such as pinholes, voids, or agglomerates. 

Many types of devices are commercially 

available or in development to meet these 

measurement needs, most of which are for 

point measurements. Laser-based 

measurements are often used for thickness, 

edge location, and alignment. Lasers typically 

probe only a single point (e.g., “triangulation” 

type gauges), but more recently “sheet” lasers 

of up to two inches width are becoming 

available to measure a local height profile or 

edge. A wide variety of other optical systems 

exist, especially for film and multi-layer 

thickness measurements. These devices are 

often based on interferometric physics and in 

some cases have the ability for spectroscopic 

interrogation. Devices based on various nuclear 

and X-ray point sources are widely available to 

measure coating thickness or weight and 

elemental composition. Beta and gamma 

gauges as well as XRF devices are well-known 

examples.

Two examples of non-uniformities in 

materials 

Photos by Michael Ulsh, NREL

 

Reflectance-based wafer monitoring system

Photo from Michael Ulsh, NREL
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As mentioned above, the criticality of a particular measurement will determine how the device or 

devices are configured. In many cases, a single point measurement of the web is considered 

sufficient. In other cases, several point measurements are made at static locations across the web. 

In a final configuration of point measurements, which is often utilized with nuclear or X-ray 

sources, the source and detector are mounted on a linear motion device and rastered back and 

forth across the web. This final configuration is particularly useful for identifying die lines or 

other systemic variations that are continuous in the direction of motion. However, when discrete 

types of variability can cause significant performance or lifetime effects, point measurements 

may not be sufficient. In this case, areal or imaging-based measurements are required. “Machine 

vision systems” are widely known and used; they consist simply of a video camera coupled with 

front or back lighting and complex image processing algorithms. For defects characterized by 

visual contrast from their background, these systems are often sufficient and highly valuable. 

However, in many cases, more complex measurement techniques using CCD or pixel-array 

detectors are used or in development. In some cases, these systems use light as a source and can 

operate using reflective, transmissive, or absorptive modes. Detectors are, in some cases, also 

available for ultraviolet, IR, and X-ray based measurements. Figure 6 shows an example of a 

reflectance-based optical measurement showing grain boundaries and orientation on a silicon 

wafer surface. In addition, line detectors (i.e., a linear array of pixels) increasingly are available 

at various wavelengths that in some cases provide a higher pixel density than two-dimensional 

array detectors, and these can be used if a line measurement is sufficient.

Figure 6. Optical reflectance measurement of silicon wafer grain boundaries

In most cases when line or array detectors are used to make measurements other than visual 

wavelength images or videos, an excitation source is used to excite some measureable response 

from the surface or layer of interest. Various wavelengths of electromagnetic radiation can be 

used, as discussed previously. An electronic excitation can be used either to make a functional 

measurement of an electrical property or to excite a thermal response via Joule heating that can 

be detected using an infrared CCD detector. Figure 7 shows an example of this latter case for a 

fuel cell electrode with a void. Similarly, a thermal heat source can be used to heat the material 

directly and, in specific cases where it is relevant, a reactive excitation can be used to generate a 

thermal signature.
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Figure 7. Thermal signature of fuel cell electrode with a void using electrical excitation and IR CCD 

detector 

Status of EERE Activities

Workshop planning team members from each of the five EERE offices were queried to 

determine the status of previous and current activities in their offices related to the workshop 

scope. The offices were asked to provided information about current projects, past activities to 

determine needs and barriers, and whether specific needs and barriers have been addressed in 

program-wide plans as targets, tasks, goals, or milestones. This detailed information is given in 

Table 1 and was presented in summary form to the workshop participants to further inform them 

of the status of EERE activities across the different offices.

Table 1. Summary of EERE Activities

Question Office Response

Ongoing QC 

projects 

AMO Current projects:

• Penn State University—Additive Manufacturing (NAMII, now 

America Makes) expands the use of thermal imaging for process 

monitoring and control

• ORNL Manufacturing Demonstration Facility Projects

Recent QC efforts funded by the Industrial Technologies Program 

“Grand Challenge” portfolio:

• Next-Generation Wireless Instrumentation Integrated with 

Mathematical Modeling for Use in Aluminum Production 

(Wireless Industrial Technologies, Inc.)

• Advanced Optical Sensors to Minimize Energy Consumption in 

Polymer Extrusion Processes (Guided Wave, Inc.)

BTO • The windows and building envelope program within BTO does 

not have any active projects specifically related to QC. 

• Process-related activities in BTO:

o NREL—VI Window Film 

o ITN Energy Systems—Low-Cost, Highly Transparent 

Flexible low-e Coating Film to Enable Electrochromic 

Windows with Increased Energy Savings 

o Industrial Science & Technology Network, Inc.—A New 
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Generation of Building Insulation by Foaming Polymer Blend 

Materials with CO2

o Pacific Northwest National Laboratory (PNNL)—Dynamically 

Responsive IR Window Coatings

FCTO • NREL—Fuel Cell Membrane Electrode Assembly (MEA)

Manufacturing R&D

• LBNL—Manufacturing R&D for MEAs (sub to NREL)

SETO • Spire Corp—Photoluminescence for Solar Cell Crack Detection

• Janoch Engineering, Inc.—In-Line Light Beam Induced Current

• Sinton Instruments—Device-Physics-Accurate Cost-Effective 

and Module Test Instruments

• MicroXact, Inc.—Real Time PV Manufacturing Diagnostic 

System

• Tau Sciences Corporation—Apparatus for Optimizing PV Solar 

Manufacturing Efficiency through Real-Time Process Feedback 

and Spectral Binning 

• Plant PV—Three Dimensional Minority Carrier Lifetime Mapping 

of Thin Film Semiconductors for Solar Cells Application

VTO • ORNL—Lithium Ion Electrode Production Non-Destructive 

Evaluation and Quality Control Development

QC needs and 

barriers 

identified? (With 

industry 

participation or 

validation?) 

AMO • Road-mapping process conducted by NAMII and a topic added 

to the current open project call

• The Industrial Technologies Program (AMO’s predecessor) had 

a dedicated program activity entitled “Sensors & Automation” 

that funded R&D activities and also engaged industrial 

stakeholders 

BTO Yes, this was identified as a need/barrier at:

• Windows and Building Envelope Roadmap Workshop (April 

2013)

• CEMI Midwest Regional Summit (June 2013)

FCTO Yes, Hydrogen and Fuel Cell Manufacturing R&D Workshop (August 

2011)

SETO SunShot Metrology Workshop (February 2012)

VTO Non-destructive techniques for the evaluation of the integrity of joints 

need further development (Multi-Year Program Plan, December 2010)

Documented 

office-wide 

specific targets, 

tasks, goals or 

milestones 

relative to QC?

AMO No specific targets, tasks, goals, or milestones related to QC are 

currently included in AMO’s planning documents

BTO No

FCTO Yes. Manufacturing R&D chapter in FCTO Multi-Year RD&D Plan 

including goals, targets, tasks, and 

milestones. http://energy.gov/eere/fuelcells/fuel-cell-technologies-officemulti-year-research-development-and-demonstration-plan

SETO SunShot vision study outlines $/W or levelized cost of electricity targets 

for solar. QC has an impact on yield and hence manufacturing 

cost. http://www1.eere.energy.gov/solar/pdfs/47927.pdf 

VTO No

Additional 

comments 

concerning the 

relevance or 

importance of QC.

AMO Suggest workshop discussion on QC needs be primarily focused on truly 

cross-cutting areas where multiple offices would benefit. QC efforts 

should also consider broader discussion beyond EERE, such as 

inclusion of the National Institute of Standards and Technology (NIST),

which conducts a variety of activities in the manufacturing metrology 

space (e.g., http://www.nist.gov/manufacturing-metrology-portal.cfm).

BTO Future non-vapor compression systems will bring a lot of new joining 

challenges to HVAC, water heating, and appliances. Better joining 
15 

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techniques and testing these new joints will require new QA/QC testing 

procedures. A workshop that includes joining will allow manufacturers to 

communicate challenges to enable moving toward higher-performing 

(more efficient) designs and identifying reliable and cost effective 

techniques.

FCTO None

SETO QC methods to improve efficiency and yield and lower cost are very 

relevant to achieving SunShot goals. Our program currently funds 

projects under multiple funding opportunity announcements (FOAs) on 

this cross-cutting topic.

VTO The R&D community needs to produce other innovative in-line nondestructive evaluation techniques such as XRF, particle size 

measurements, FTIR, Raman.

The responses span a range of previous activities, likely related to the deemed criticality of 

manufacturing issues in the development and advancement of the different technologies. The 

impact of the breadth of materials and systems relevant to the different technology offices is also 

seen. For example, sheet materials such as window films are only a small fraction of the vast set 

of materials, systems, and technologies that are supported by the BTO for buildings. 

Preliminary Industry Inputs

As an additional preliminary data gathering step, the workshop planning team decided to develop 

a short questionnaire for a small set of stakeholders. The intent of the questionnaire was to gain 

additional understanding of the status and implementation of in-line QC techniques for these or 

related technologies to aid the team in setting the structure and most useful discussion threads for 

the workshop breakout sessions. A summary of the responses to the preliminary questionnaire is 

given in Table 2. 

Table 2. Industry Responses to Questionnaire 

Question Response 

What materials are being produced in-line in a 

roll-to-roll process, what processes are being 

used to manufacture the materials, and what 

are the critical measurements of interest? 

• Materials:

o Bipolar Plates

o Electrodes 

o Electrochromic films

o Thin film flexible solid state batteries

o Flexible thin-film copper indium 

gallium selenide (CIGS) based PV

o Transparent conducting oxide and 

moisture barrier films

o Non-woven fabrics textiles and films

• Measurements of interest:

o Micro-cracks

o Catalyst homogeneity, pinholes

o Band gap

o Open circuit voltage

o Conversion efficiency

o Surface sheet resistance

o Optical transmission measurements

o Areas of roping (congealing) 

What techniques are used in industry to 

identify and quantify defects in materials?

• Vision detection systems for cracks

• Fluorescence of functional coatings applied to 
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textiles

• Non-contact eddy current measurements for 

surface sheet resistance

• Non-contact optical measurements for band 

gap and relative thickness of coatings

• Non-contact XRF for composition and also 

thickness of coatings

• Photo-imaging for physical defects 

What issues exist with the current quality 

assurance/quality control techniques?

• Lack of standards. A few companies sell 

cameras and algorithms, but not necessarily 

tuned to the application

• Hardware exists. Main gap is software 

relevant to specific application

• Need to be able to scan for the composition of 

coatings (for multi-material coatings) and 

physical defects across full width and length 

of web while web is in motion

What measurements are needed for in-line 

quality control that current techniques do not 

address? 

• Physical defect density and/or pinhole density 

• Band gap measurements 

• Surface sheet resistance of coatings

• Optical transmission 

• Relative thickness of coatings across and 

along the length of the web 

• Material composition measurements 

• Networking-cloud data transmission

Industry Panel Session

This section provides a summary of the industry panel session. Panel members were selected 

across multiple technologies and with backgrounds representing manufacturing, QC device 

development, and research. Questions for the panel were predetermined and are given below in 

Table 3 along with the names of the moderator and panel members. Panel responses to these 

questions are given in Table 4. After the moderated Q&A session, the session was opened to the 

workshop participants for additional Q&A, and these questions and responses are summarized in 

Table 5. 

Table 3. Industry Panel Discussion Session

Industry Panel

Moderator: Arrelaine Dameron, NREL

Panelists:

• Everett Anderson, Proton OnSite, maker of PEM electrolyzers for hydrogen production

• Bogdan Lita, Consultant, formerly of GE Primestar, maker of thin film PV

• David Gotthold, PNNL, formerly in semiconductor industry

• Ron Sinton, President of Sinton Instruments, maker of measurement devices for PV 

manufacturing

Panel Questions

1. What types of QC have you found critical and which are useful in-line?

2. Are there specific technical aspects of the manufacturing processes where current QC methods 

don’t work well (i.e., line speed, temperature, etc.)?

3. What are the economic considerations in choosing to implement in-line QC?
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Table 4. Summary of Key Points from Moderated Panel Session

Panel Question Panel Comments

1. What types of QC have you found 

critical and which are useful in-line?

• Existing thickness measurement techniques are not 

accurate enough for thin films (e.g., 10s of 

nanometers for organic light emitting diode coatings) 

• Large area thickness measurement is important for 

thin films

• Need to measure platinum group metal catalyst

loading in electrode coatings

• Need to understand how to measure the quality of 

advanced material structures (e.g., binder 

morphology) 

• The move toward higher efficiency silicon technologies 

will necessitate additional/new QC techniques

• There is very little understanding of the correlation 

between the defects detected on-line and the effect on 

the expected 20 year lifetime (of PV)

• Many materials still use batch processes and no inline QC

• Processes are still changing for many of these 

materials—there will continue to be new or different 

measurement needs

• Precision and repeatability of measurements are more 

important than accuracy

• The use of statistical process control, in particular 

analysis of process capability, does or can determine 

needed frequency of measurement

• For thickness or composition, a point works well to 

look for process drift

• The two techniques (point and areal measurements) 

are complementary for silicon: point gets you a 

number, areal gets you an image (uniformity)

• Identifying defects in black surfaces on black 

substrates is difficult for optical methods

• Methods to locate an edge or alignment of edge are 

needed

• There has been a push to use in-line imaging on PV 

lines, but it hasn’t happened yet to any great extent

2. Are there specific technical aspects of 

the manufacturing processes where 

current QC methods don't work well 

(i.e., line speed, temperature, etc.)?

• Fabrication tools generate heat as part of process: 

need measurements that can be independent and 

tolerant of process temperature

• Process condition considerations: high vs. low 

temperature, wet vs. dry, vacuum vs. atmospheric 

pressure

• (For polymer electrolyte membrane [PEM] electrolyzer 

MEAs) Electrodes are fabricated while the materials 

are wet: QC becomes difficult

• Being able to make measurements at process speeds 

is important: but measurements are always “not fast 

enough”, regardless of line speed

• Speed not as critical for early market technologies

(e.g., hydrogen production equipment)
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3. What are the economic considerations 

in choosing to implement in-line QC?

• QC must be applied when it can affect yield

• We don’t want to make scrap, especially with very 

expensive raw materials

• Perception or observation that in industry, in-line data 

is ignored because they don’t want to shut down the 

equipment just because the measurement is showing 

something out of spec—“the measurement must be 

wrong”

• Using in-line data in a feedback-loop to control 

equipment is ideal, but not really happening

• Perception or observation that industry uses metrology 

to help optimize the process, but once the line is 

running, they turn the measurements off

• Use of in-line QC to some extent depends on the 

commodity level of the material: lower price = measure 

less

Table 5. Summary of Audience Q&A Session with Panelists

Audience Question Panel Answer

Are there specific QC/metrology needs for clean 

energy products?

QC techniques may have to be aligned to specific 

technologies, but generically they must all be noninvasive and cannot slow down the line.

Scaling up processes means transitioning from 

human to software-based decisions—are software 

control systems ready?

It’s happening but still at the R&D level. Needs to 

be cheap as well as fast and accurate.

We need to discuss process control and feedback. 

If we’re not measuring or providing feedback, the 

process isn’t controlled. How realistic is in-line 

process control with these complex systems?

(a) There are off-line measurements for voltage, 

open cell voltage, thickness, and resistivity at each 

part made to make sure the process is in control 

and to measure for batch-to-batch variation/impact. 

(b) Determination of “in control” doesn’t need to be 

in-line—it’s easier to do off-line, but we should 

hope to move more in-line.

(c) If finished product shows something wrong, 

where did the process go bad? Would like in-line 

measurements to identify where in the process or 

at which process step things go bad.

These clean energy industries are immature 

compared with others (e.g., steel making, auto 

industries). Six-sigma has not been built in to all of 

the process steps. Are there lessons learned?

Don’t know where to start with lessons learned for 

the steel industry. PV is immature—there have 

been large changes made in a short amount of 

time. It is not yet understood how to predict how 

these changes will affect the final product.
19 

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Summary and Key Learnings from the Breakout 

Sessions

Three breakout sessions were held to engage the workshop participants in creative and critical 

discussions on QC needs and opportunities for the materials of interest for the workshop. 

Breakout 1 was intended as a technology-specific review of QC challenges. As such, four 

separate sessions were held, attended by the industry, lab, and DOE participants associated with 

each of the four technology offices. Breakout 2 was a discussion of similarities among 

measurement and inspection needs across the different technologies and of whether synergies 

may exist where QC technologies or techniques in development for one technology may be 

useful for another technology. To enable cross-cutting perspectives, the participants representing 

the technologies of each office were mixed together in three identical groups. Finally, breakout 3 

was an assessment of quality control needs that are not being addressed by current development 

activities and a discussion of ways that industry together with EERE can move ahead in 

identifying and supporting cross-cutting QC development activities. This session was attended 

by the same three mixed groups as for breakout 2. Each session was led by a facilitator and 

assisted by a scribe. In the sections below, the discussion questions, summary outputs, and key 

learnings from each breakout are presented and discussed. Detailed notes from each of the 

breakout sessions are given in Appendix C. 

Breakout 1: QC Challenges

Table 6 shows the objective, questions, and discussion threads posed to the participants in each 

of the breakout 1 groups. The purpose of this breakout was to provide each technology group an 

opportunity to review previous activities supported by their office to identify QC needs and 

barriers, to discuss the overviews presented earlier in the workshop, and to propose any needs 

that were not previously identified.

Table 6. Objective and Discussion Questions for Breakout Session 1: QC Challenges

Breakout 1 Objective: Produce a prioritized list of QC challenges for your technology area

Questions and discussion threads:

• Many of the offices have supported manufacturing workshops or other data gathering activities in 

the past few years—review these outcomes, especially if QC, measurements, and metrology 

were discussed.

• Current office activities in this area were summarized earlier in the workshop—are there any 

comments, questions, or discussion about those activities?

• Overviews of current processes and QC techniques were given earlier in the workshop—are 

there any comments, questions, or discussion about what was presented in those overviews?

• Do any of you have any additional thoughts or inputs in regard to what QC challenges exist in our 

technology area that may not have been captured in the overviews or the previous DOE 

information-gathering activities?

Table 7 shows the summarized responses from the breakout by technology group. Given the 

differences in status and maturity of each of the technologies, the specific materials and 

processes of interest to each group, and the activities that each office has chosen to pursue in the 

past relative to manufacturing and quality issues, it is not surprising that the outputs of the 
20 

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different groups varied significantly. However, several key topics emerged that were similar 

across the groups and could be taken as cross-cutting learnings. 

• Most of the groups identified “understanding the effects that specific types of defects will 

have on cell/device performance and lifetime” as a critical need. Associated with this 

need was an improved understanding of the role that accelerated testing can and/or 

should play and the need for development of methods to mark defects for later removal. 

• While expressed in different ways by different groups, the participants identified a 

general need for better ways to quantify the return on investment associated with 

developing and implementing in-line QC, especially given the currently small production 

volumes of many of the technologies of interest. An exemplary anecdote was given of a 

company that decided to leave a cheap gate valve in a system because it was less 

expensive to replace the few that failed than to include a more expensive valve in each 

system.

• There was a general assessment that many of the critical QC needs were related to 

functional rather than dimensional measurements, with the exception of layer or coating 

thickness. 

Table 7. Summary Responses from Breakout Session 1 by Technology Group

Technology Group Responses

SETO (this group 

voted on most 

important items in 

discussion, as 

indicated in 

parentheses)

• Understanding of defects with respect to product performance (Everyone)

• Cost of new QC technology implementation and return on investment 

(Everyone)

• How do defects affect the expected reliability over decades of expected 

lifetime (4)

• Speed of QC data acquisition (4)

• Resolution of measurement techniques/field of view (3)

• Challenges to justify cost of QC due to size of market 

• Observation thermography for detection of solar cell shunts, shorts

• Optical defects can be significant: deviation in color, optical flatness, 

bubbles, voids

• Need improved sensitivity of sensors, along with algorithms for the sensors,

to detect defects

• How many and what type of defects matter? 

• Can a Pareto chart with main types of defects be developed?

• Algorithms must be able to evaluate between number, type, and criticality of 

defects

• “X” defect will do “Y” to the system is not always known

• Provide service instead of tools? Prepay for consulting services to help 

instruct the users on the proper use of the equipment?

• Return on investment—customers don’t see the cost benefit of having 

correct QC/metrology

• Return on investment—lump in with cost of new technology? 

FCTO • Difficult to measure electrochemical properties of solid oxide fuel cells

(SOFC) in-line (need to bring up to operating temperature)

• Dimensional metrology is well understood; thickness, height, dimensions can 

be measured
21 

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• Membranes: limited pinhole detection; mainly rely on supplier

o Pinhole length scale is not well understood; isn’t clear what size 

results in failure

• Bipolar plate:

o Detecting micro-cracks

o Measuring nitride (anti-corrosion) layer thickness

o Degree of planarity/flatness

o Leak checking

• Electrodes: thickness and catalyst content

• Gaskets and seals: need better understanding of what properties lead to 

better performing seals

• Need to correlate defects to performance loss or degradation

• Need further development of accelerated testing methods for all components

VTO • Key defects/criticality:

o Metals from mixing/slitting debris causing short circuit, overheating. 

Effects can be grave, but seldom happens. Possible metrology: 

optical, thermography

o Coating defects (pinhole, blister, porosity) from mixing, slurry 

process affect life, medium gravity/frequency

o Material agglomerates from slurry affect safety, medium 

gravity/frequency

• May need to mark scrap material—a lot of material scrapped due to false 

positives

• Performance or quality of battery: has this been mapped back to defects?

• How much can we learn from other technologies? 

BTO • Accelerated aging tests 

• Embedded sensors to provide real-time data

• “Buildings” is a very large topic with many components; treat building like a 

system

• Environmental and public pressures on manufacturers to change a material 

and/or product make developing QC for specific materials difficult

Breakout 2: Synergies

Table 8 shows the objective, questions, and discussion threads posed to the participants in each 

of the breakout 2 groups. The purpose of this breakout was to determine if, and in what ways, 

synergies existed between the QC needs and/or capabilities of one technology and the needs 

and/or capabilities of the other technologies. For example, in a collaboration exemplified during 

the overview talks, NREL has previously taken QC techniques developed for in-line inspection 

of PV wafers and, with modifications appropriate to the differences in the materials, developed 

and demonstrated techniques useful for fuel cell membranes and electrodes. These kinds of 

opportunities, across offices, manufacturers, QC device makers, and labs, are being sought by 

breakout 2. 
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This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Table 8. Objective and Discussion Questions for Breakout Session 2: Synergies 

Breakout 2 Objective: Produce a prioritized listing of possible synergies

Questions and discussion threads:

• We just heard summaries of the most critical challenges and needs from each of the technology 

areas—are there any initial thoughts or comments?

• Discuss what we mean by synergies

• Are there any initial thoughts about synergies when you look at the challenges across the 

different technologies?

• List any ideas you have of where a technique that is available or being developed for one material 

or technology may be applicable to a different material, keeping in mind the key challenges we 

heard about earlier

• Again, given what we’ve heard about key challenges, we’d like to get your input on prioritizing 

these ideas 

• What ideas do you have about facilitating different companies or researchers from different areas 

getting together to address these potential synergies?

Table 9 shows the summarized responses from the breakout by group. While each group pursued 

a slightly different path in its discussion, many similar themes emerged across the three groups. 

Key synergistic opportunities, based on the types of measurements needed for the different 

materials, were identified as follows: 

• Measurement of thickness

• Inspection for “mechanical” defects such as pinholes and cracks

• Optical measurements of texture, morphology, and surface structure

• Measurement of electrical properties.

In general it was recognized that all techniques need to be rapid, non-contact, and nondestructive. Associated with these similarities, however, the groups identified several key 

factors that must be taken into consideration when assessing and pursuing potential synergies. 

• Relative to the critical measurement of thickness, the groups pointed out that the 

difference in length scale between the thicknesses of, for example, thin film PV layers 

and coatings for battery or fuel cell electrodes may span three or more orders of 

magnitude, from 10s of nanometers to 10s or 100s of micrometers. 

• Relative to electrical measurements, the groups pointed out that in the case of PV cells, 

actual voltage measurements are desired based on the junctions deposited on the wafer. 

On the other hand, for battery and fuel cell electrodes, no ex situ voltage exists. Rather, 

measurements of electrical properties such as in-plane and through-plane resistance are 

needed. 

• Differences in the criticality of similar types of defects or non-uniformities across the 

different applications were identified. For example, one group pointed out that a pinhole 

in a layer of a PV device may have a small performance effect, but the same-size pinhole 

in a battery separator may cause failure.

Additional synergistic considerations were identified, including restatement of some of the 

themes from breakout 1. 
23 

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• The cross-cutting needs to better understand the effects of defects on performance and to 

have tools and methods to quantify the value of QC in low-volume markets were 

repeated. 

• The linkage of QC measurements to process control, and more broadly the acquisition, 

analysis, and use of large quantities of data in a continuous manufacturing environment, 

was seen as a need across all of the technologies. 

• The need for improved sensitivity of devices was also identified as cross-cutting—not 

only sensitivity to smaller length scales, but sensitivity to lower levels of contrast. One 

group discussed the impact of developing cameras and software that can “see and 

evaluate” differences like the human eye and brain can. 

Finally, there were several administrative ideas about how to more efficiently identify and 

initiate synergistic activities between vendors and researchers who supply and/or develop QC 

techniques, but who rarely get to interact because they support different technologies or 

different offices. In general the suggestion was for DOE to support follow-on activities to the 

workshop of a much more technical nature to facilitate relationship building and a more detailed 

level of understanding of what capabilities exist, what is under development, and what 

similarities may be exploited.

Table 9. Summary Responses from Breakout Session 2 by Group

Group Responses

Group 2A • Topography—similar for batteries and fuel cells?

• Thickness measurements of different scales—nanometer vs. micrometer

• Measurements related to texture, scattering (PV, fuel cells, batteries)

• Intellectual property issues are ever-present for universities or labs trying to work with 

industry

• Pre-commercialization is a good time for labs and universities to develop process 

control systems—before a company scales up

• Who is responsible for making QC checks (the device maker or the material supplier)? 

• In-line X-ray measurement 

• For PV, electrical measurements made of actual device voltage once connections are 

made on cell—for fuel cell and battery, would need in situ test for voltage, so want to 

make measurements of electrical properties, not actual voltage measurement

• Some defects accelerate failure 

• Exchange of technical methodologies needed between researchers

• Smaller technical meetings (or webinars) to discuss methodology and how one new 

device/process could be adopted by others either in their field or across technologies

• National lab summit

• Not high enough volumes yet to readily delve into looking at these issues

• Electrical or electronic measurements important

• How and when in the process should these measurements be taken?

• Carve out a session at this year’s Hydrogen/Vehicles Programs’ Annual Merit Review? 

What about doing a national lab webinar series?

• Each office needs to better understand the impact of defects on performance and 

durability to correlate those defects to not only reduced scrap/higher yield, but also to 

some kind of cost benefit

Group 2B • Method needs to be non-invasive, non-contact, fast

• Correlation of defects to performance is not clear

• Common problems are difficult to define due to different applications
24 

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• Coatings have common mechanical problems: pinholes, cracks

• Does defect affect performance later or result in immediate problem? 

• Cost of defect detection has to be lower than cost of defect—perceived return on

investment

• 10 nm scale thickness needed for thin films

• Commonality between applications

o Pinholes, micro-cracks

o Critical defects for different applications might differ in size

o Compositional homogeneity

o Reliability

o Accuracy, false positive avoidance

o Statistical quality control is required to perform metrology effectively

Group 2C • Although there are synergies across the technologies, they are application specific. For 

instance a type of defect might be catastrophic to one technology, but not to another

o Pinhole is limited in how it will affect solar technologies; for battery it could kill 

the entire battery

• Quality of deposition, registration of layers

• Techniques for leakage and pinholes

• Not enough understanding of long term aging effects

• Inspection systems that approximate the acuity of human vision system would probably 

solve problems in the industry across all technologies

Breakout 3: Remaining R&D Needs and Recommendations

Table 10 shows the objective, questions, and discussion threads posed to the participants in each 

of the breakout 3 groups. The purpose of this breakout was to identify critical quality control 

needs that are not being addressed by currently-in-development activities and to suggest 

directions and actions that industry together with EERE can take to identify and support crosscutting QC development and demonstration activities.

Table 10. Objective and Discussion Questions for Breakout Session 3: 

Remaining R&D Needs and Recommendations

Breakout 3 Objective: Produce a prioritized listing of R&D needs for EERE to address, identifying 

those that are cross-cutting

Questions and discussion threads:

• We’ve just heard summaries from the first two breakouts of the workshop—are there any 

comments or discussion?

• Breakout 1 discussed QC challenges and we’ve heard about existing or developmental QC 

techniques that do or may address these challenges—are there key measurement and inspection 

needs that aren’t being met by commercially available techniques or EERE-supported technology 

development efforts? 

• Could any of the techniques that have been discussed be applied to these needs?

• Are there techniques that haven’t been discussed that may be applicable?

• Are any of these needs cross-cutting?
25 

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Table 11 shows the summarized responses from the breakout by group. In terms of missing 

capabilities, while many needs undoubtedly still exist, the main discussions centered around 

three main areas:

• Inspection for delamination, inter-layer voids, and bond strength, noting that almost all of 

the materials of interest to the workshop are multi-layer in construction (either fabricated 

in successive layers or laminated) 

• Machine vision systems that can replicate the human eye—and going beyond, further 

development of inspection techniques that are not limited by optical wavelength

• Improved tools and methods to collect, analyze, store, and use the large amounts of data 

generated by in-line QC, with additional discussion of “post-production” data mining to 

identify the sources of product failure or poor performance in the field. 

Table 11. Summary Responses from Breakout Session 3 by Group

Group Responses

Group 3A • Pinholes/defects that do not seem to be an issue at the time the device is manufactured 

but rather as the device works

• Delamination of multi-layer structures; layer-to-layer bonding/adhesion

• Bond strength may be difficult to measure in-line while void detection may be easier to

observe in-line

• Acoustic tests: each sample has its own resonance curve, adhesion defects will show in 

a modified resonance

• What will DOE do with these ideas? Support for cross-office activities

• Find lessons-learned from Europe, where large collaborative scopes are more common

• Make teaming necessary for FOAs?

• Need buy-in from manufacturers and tech transfer to industry, enabled by Small 

Business Innovation Research (SBIR) funding?

• Improve collaboration mechanisms between industry, vendors, and researchers

• Cost benefit of QC

o Use manufacturing cost analysis, if QC is included in models?

o What is the cost of not having QC? Real processes never have 100% yield, but 

the manufacturers never give out the exact yield—business sensitive 

o Example of fuel cell stack yield vs. increase in stack costs; if QC measures are 

not taken, the percentage of bad product significantly increases costs

• Set up more fabrication labs to investigate the use of QC/metrology in manufacturing 

setting

• Intellectual property issues undermine collaborations and effective teaming

• A major challenge/barrier to working on synergistic research topics is how the Annual 

Operating Plan (for DOE labs) process works

o Encourages principal investigators to work inside their silo

o Need some sort of shareable Annual Operating Plan

o Also need better support for working with industry partners

Group 3B • Process control development is still a need

• Example of a Defense Advanced Research Projects Agency (DARPA)-supported

consortium with nine companies to look at vapor phase manufacturing of CIGS and how 

to control four element deposition correctly

• Offline techniques might be available—how to bring them online? 

• BTO has more of a focus on equipment design to improve the energy efficiency of a 
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piece of equipment or appliance than on QC or metrology as a subject, though QC

might be used or needed for a product

• Catalogues needed of available QC techniques

• Understanding lacking on the laboratory side about industry/manufacturing needs

• Manufacturer does not want metrology on their line: only accepted if there is an impact 

on their productivity and bottom line; if they have a problem and it hurts

• Most QC techniques signal a problem but do not give guidance for correction

• Must have collaboration with manufacturer

• Need software enabling use of in-line data for process control

Group 3C • Vision system that replicates the processing ability of human brain/eye

• Detect things smaller than the diffraction limit of what the human eye can detect

• Look at physical features in intermediate scales (looking at small things over large 

areas—one defect in a vast area)

• How to store measured data now to be analyzed later?

• Use big data mining techniques to accumulate a lot of data

• Oversample and then try to look back at the data 

• Go back in time and see what is statistically significant—large data set may show 

trends, but we need the data set first

• Getting process equipment manufacturers to work more closely with QC vendors

• Define a real vs. a perceived defect. What’s a variation vs. an actual defect?

• We throw out a lot of material from being too conservative with perceived defects 

• Generate a table that summarizes QC techniques and their capabilities (defect size, line 

speeds, etc.) 

o Make a table for renewable energy technologies for defect definition, 

irregularities, how to detect them and different synergies 

o A table showing QC techniques used and how they are applied and then have 

equipment vendors and others come in and fill gaps for areas of QC that aren’t 

well defined

• Metrology webinar series under the AMO umbrella

• Taking technology from the laboratories and demonstrating it at real companies for a 

brief period

• Could make companies hesitant because of QC issues that get sampled—

manufacturers don’t necessarily want their defects or manufacturing issues to be known 

by the outside

Looking forward, the groups discussed numerous issues for EERE and industry to collectively 

overcome to more effectively pursue impactful cross-cutting QC RD&D. One broad category of 

ideas centered on improving collaboration with industry. Participants noted that manufacturers 

often are hesitant to collaborate on QC issues because they do not want their manufacturing 

issues to be known. This hesitance is compounded by ever-present intellectual property concerns, 

especially when working with universities or labs. Better methods to assess and present the costof-poor-quality/cost-benefit of QC was seen as a potential way to improve manufacturer buy-in 

and ultimately lead to increased technology transfer. Similarly, the groups saw finding methods 

to foster increased interaction and integration between fabrication equipment manufacturers and 

QC vendors as a valuable direction. Finally, topics discussed in previous breakouts were echoed, 

including increased efforts in correlating defects to performance to mitigate what was stated to 

be widespread scrapping of material due to “perceived defects”, and integration of QC into 

process control.
27 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Key recommendations for EERE to facilitate better cross-technology and cross-office 

interactions were the following: 

• Evaluate and implement better ways to promote teaming across labs, industries, and 

activities—in particular, better ways for labs to collaborate within the very office-specific 

Annual Operating Plan process 

• Consider setting up focused industry/lab collaborations on specific issues, with the 

DARPA-sponsored CIGS roadmap activity as an example 

• Continue and expand SBIR topics in this area to promote industry/lab collaboration and 

technology transfer

• Catalog for clean energy technologies the types of defects and non-uniformities and the 

available QC technologies for addressing them 

• Hold a metrology webinar series and/or other means of informative outreach to improve 

manufacturers’ exposure to and understanding of available QC techniques, especially the 

small and medium enterprises that typically do not have the internal resources to pursue 

QC.
28 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Conclusions and Recommendations

The EERE QC Workshop was structured to create a common understanding of needs and 

capabilities across the technologies represented by the five offices that co-sponsored the activity 

and to facilitate creative and critical discussion regarding opportunities for EERE and industry to 

work together in addressing cross-cutting needs for in-line quality control, inspection, and 

metrology. From the overview presentations to the industry panel and series of breakout 

sessions, participants were engaged and encouraged to identify synergistic opportunities for 

collaboration and ways that industry and EERE could promote improved communication, 

collaboration, and technology transfer between labs, equipment suppliers, clean energy 

technology manufacturers, and QC device vendors. The outputs of the workshop logically lend 

themselves to categorization into conclusions and recommendations, the former taking the form 

of specific technical topics to be addressed and the latter as proposed activities for EERE and 

industry to pursue.

Conclusions

Cross-cutting QC needs: The participants clearly identified the following QC measurement needs 

that cross-cut the different technology areas and that are potential opportunities for cross-office 

collaboration:

• Thickness measurement

• Inspection for mechanical defects such as pinholes and cracks

• Measurement of electrical properties such as resistance

• Measurement of surface texture, structure, and morphology 

• Inspection for inter-layer delamination and voids. 

Participants also identified several counter-balances to these synergies—considerations that must 

be made when establishing cross-office collaborations—including: 

• Differences in scale—for example, measuring nanometer-scale layers in thin-film PV as 

opposed to micrometer-scale coatings in fuel cell and battery materials

• Differences in criticality of defects or non-uniformities between applications—for 

example, pinholes in PV layers versus in a battery separator 

• Whether or not actual performance can be made ex situ—for example, voltage 

measurement in a PV cell with junctions versus through-place resistance of a fuel cell 

membrane electrode assembly.

In addition to these specific measurement needs and considerations, the participants identified 

two higher-level technical goals:

• Improving the sensitivity of detectors to smaller size scales (i.e., from micrometers to 10s 

of nanometers) as well as to smaller levels of optical contrast
29 

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• Advancing tools and methods for the collection, analysis, storage, and use (either in real 

time or for later data mining) of high volumes of in-line QC data and for the integration 

of these data into process control and feedback systems.

Correlation of defects to performance: Throughout every part of the workshop, participants 

communicated the need for an improved understanding of the effects that defects in each of these 

materials have on device performance and lifetime. The complexity of the need was clearly 

stated, as these effects could and do depend on, for example, the shape, size, depth, extent (single 

vs. multiple defects or defects that cover large areas of surfaces), aspect ratio, and location on 

device of the defect. The fact that the criticality of similar defects in different applications could 

be very different was also clearly stated. This need implies detailed ex situ and in situ testing of 

materials as well as correlated model development efforts to increase the capabilities of 

measurement systems to not only indicate a defect but also suggest causes and steps for 

mitigation.

Cost-benefit analysis: The early market, low volume status of many of these clean energy 

technologies hinders collaboration with manufacturers in the development and demonstration of 

new and useful QC techniques, either because the companies are small and lack the internal 

expertise to address this scale-up issue or because there is a lack of funds to address an issue that 

is perceived to be important or valuable only in full-scale production. Accordingly, the 

development of tools and methods to enable a manufacturing-cost-based analysis of the cost 

benefit of in-line QC implementation was seen as a strong need. A preliminary assessment of the 

cost-of-poor-quality as a function of manufacturing volume for automotive fuel cell stacks was 

shown as an example, and it was noted that detailed manufacturing cost models have been 

developed for several of the technologies and could perhaps be utilized as a basis for these 

analyses.

Recommendations

Improve communications and interactions with industry: As noted above, a variety of factors 

hinder interaction with manufacturers on this topic, including real or perceived lack of value as 

well as very real and complex issues such as confidentiality of manufacturing activities and 

information and associated intellectual property issues. The following pathways were suggested 

to increase communication, better understand best practices, and address confidentiality issues: 

• Develop and make available—via a Web-based searchable database, for example—a 

catalog of QC techniques, their capabilities, applications, and suppliers/developers, with 

inputs from QC vendors and lab developers 

• Support continued inclusion of QC-related topics in funding opportunities and SBIR calls 

and consider focused DOE-supported industry/lab collaborations to address specific 

technical issues

• Hold webinars and post case studies on appropriate websites on QC topics and techniques 

to enhance industry’s understanding of the potential capabilities and value of QC 

implementation and to facilitate connections between the material manufacturers, QC 

vendors, and lab researchers
30 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

• Connect with other U.S. government entities who may have established best practices for 

interaction with industry on manufacturing topics, including the Advanced Research 

Projects Agency-Energy (ARPA-E), DARPA, the U.S. Department of Defense

Manufacturing Technology Program (DoD ManTech), and NIST 

• Develop QC-specific tasks within the Partner Program, a potential new effort under 

CEMI, where national lab staff can work directly with industry to develop appropriate 

tools and capabilities that can benefit the broader industry without compromising an 

individual company’s intellectual property.

Facilitate technical exchange between researchers, developers, and vendors: As noted in the 

breakout summary section, interaction and relationship development between researchers, 

developers, and suppliers is hindered because they most often work in or support only one 

specific technology or office and, for example, typically do not attend the same technical 

conferences or program reviews. Thus, technical exchange at the level of detail perhaps required 

to facilitate a deeper understanding of QC development activities, methods, and techniques—and 

to actively seek and identify synergistic activities—rarely occurs. Participants recommended the 

organization of events, potentially co-located with technical conferences or DOE reviews that at 

least some of the researchers and developers would normally attend, where scientists could 

present details of their own work, capabilities, equipment, and methods and could have group 

and one-on-one interactions and discussions with other researchers.

Participants also identified the difficulties that lab researchers, who normally support a single 

EERE office through an Annual Operating Plan that is very focused on the goals and milestones 

of that office, encounter when trying to collaborate with researchers in other technology areas to 

support cross-cutting needs. Specifically, there is a perceived lack of support, facilitation, and 

recognition/reward for such interactions by the EERE offices. Participants recommended further 

discussion on improved methods and mechanisms at the EERE level to enable effective crossoffice interactions between lab researchers. A near-term opportunity of this type is the 

developing collaboration between NREL and ORNL for in-line QC. The group aims to leverage 

the considerable capabilities at both labs in QC and process development, with an initial focus on 

addressing battery electrode QC needs. This effort brings together projects and researchers 

currently supported by FCTO, VTO, and SETO and links them with strong AMO-supported 

activities for manufacturing development at ORNL, potentially providing a pilot for broad, crossoffice EERE collaboration in this important enabling topic area of advanced manufacturing. 
31 

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References

1. “Report to the President on Capturing Domestic Competitive Advantage in Advanced 

Manufacturing,” President’s Council of Advisors on Science and Technology, July 2012. 

2. “National Network for Manufacturing Innovation: A Preliminary Design,” National Science 

and Technology Council and Advanced Manufacturing National Program Office, January 

2013. 

3. “Report to the President on Ensuring American Leadership in Advanced Manufacturing,” 

President’s Council of Advisors on Science and Technology, June 2011. 

4. Department of Defense, Quadrennial Defense Review Report, February 2010, p.103. 

5. “A National Strategic Plan for Advanced Manufacturing,” National Science and Technology 

Council, February 2012. 

6. “Manufacturing Demonstration Facilities Workshop,” DOE Advanced Manufacturing Office, 

March 12, 2012, Chicago, IL. 

7. “Production in the Innovation Economy,” MIT Club of Washington DC—Annual Seminar 

Series, November 13, 2012. 

8. “Report of the MIT Taskforce on Innovation and Production,” February 2013. 

9. “Membrane Technology Workshop Summary Report,” DOE Advanced Manufacturing 

Office, November 2012. 

10. “2011 NREL/DOE Hydrogen and Fuel Cell Manufacturing R&D Workshop Report,” DOE 

Fuel Cell Technologies Office, February 2012. 

11. “Metrology Workshop Report,” DOE SunShot Program, February 7, 2012, Crystal City, VA. 

12. “Solid-State Lighting Research and Development: Manufacturing Roadmap,” DOE Building 

Technologies Office, August 2012. 

13. Fuel Cell Technologies Office Multi-Year Research, Development and Demonstration Plan, 

Chapter 3.5: Manufacturing R&D, 2012. 

14. “Manufacturing the Future-Federal Priorities for Manufacturing R&D,” National Science and 

Technology Council, March 2008. 
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Appendix A. Workshop Agenda

EERE QC Workshop Agenda

December 9–10, 2013

NREL, Energy Systems Integration Facility

Monday, December 9

8:00 Sign-in and continental breakfast

8:30 NREL welcome: Keith Wipke, Lab Program Manager, NREL

8:50 EERE welcome: Nancy Garland, FCTO; Joe Cresko, AMO

9:15 Intro to the structure and objectives of the workshop: Cassidy Houchins, SRA

9:30 Overview of current processes: Michael Ulsh, NREL

9:50 Review of Oak Ridge process and QC activities: David Wood, ORNL

10:05 Morning break and networking

10:20 Overview of current in-line QC: Michael Ulsh, NREL

10:45 Summary of current QC activities in EERE: Cassidy Houchins, SRA

11:05 Industry Panel: Quality Control for Clean Energy Manufacturing

Moderator: Arrelaine Dameron, NREL

Panelist: Everett Anderson, Proton OnSite

Panelist: Bogdan Lita, Consultant, formerly of GE Primestar

Panelist: David Gotthold, PNNL

Panelist: Ron Sinton, Sinton Instruments

12:00 Lunch

1:00 Breakout 1: QC challenges by technology area

1:50 Break/pause for breakout 1 summaries

2:00 Report-out on breakout 1 (3 or so minutes for each breakout)

2:15 Breakout 2: Synergies across technologies

3:15 Break/pause for breakout 2 summaries

3:25 Report-out on breakout 2 (5 or so minutes for each breakout)

3:50 NREL tours

5:00 Adjourn

Tuesday, December 10

8:00 Continental breakfast

8:30 Summary from breakouts 1 and 2: workshop planning team

9:00 Breakout 3: R&D needs for QC techniques

10:15 Break/pause for breakout 3 summaries

10:25 Report-out on breakout 3 (5 or so minutes for each breakout)

10:50 Closing remarks: workshop planning team

11:15 Adjourn
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Appendix B. List of Attendees

Name Organization 

Jesse Adams Fuel Cell Technologies Office, DOE

Everett Anderson Proton OnSite

Joe Berry National Renewable Energy Laboratory

Jim Bogert Fischer Technology

Michael Bolen Solar Energy Technologies Office, DOE

Antonio Bouza Building Technologies Office, DOE

Karen Buechler ALD NanoSolutions, Inc.

Kim Cierpik CAS-Navarro Joint Venture

Joe Cresko Advanced Manufacturing Office, DOE

Arrelaine Dameron National Renewable Energy Laboratory

Claus Daniel Oak Ridge National Laboratory

Ralph Dinwiddie Oak Ridge National Laboratory

Peter Faguy Vehicle Technologies Office, DOE

Halden Field PV Measurements, Inc.

Nancy Garland Fuel Cell Technologies Office, DOE

Dave Gotthold Pacific Northwest National Laboratory

David Hardy Advanced Manufacturing Office, DOE

Stephanie Hodge CAS-Navarro Joint Venture

Cassidy Houchins SRA

Carlos Jorquera Boulder Imaging

Dennis Kosisko Dr. Schenk

Dean Levi National Renewable Energy Laboratory

Bogdan Lita Consultant

Daryl Ludlow Rensselaer Polytechnic Institute

Wil McCarthy Ravenbrick

Ashutosh Misra ITN Energy Systems

Nathan Moore CAS-Navarro Joint Venture

Shaun Onorato CAS-Navarro Joint Venture

Sergei Ostapenko Ultrasonic Technologies

Ahmad Pesaran National Renewable Energy Laboratory

Yarom Polsky Oak Ridge National Laboratory

Mark Richards FuelCell Energy, Versa Power Systems

Shriram Santhanagopalan National Renewable Energy Laboratory

Ron Sinton Sinton Instruments

Bhushan Sopori National Renewable Energy Laboratory

Robert Tenent National Renewable Energy Laboratory

Michael Ulsh National Renewable Energy Laboratory

Maikel vanHest National Renewable Energy Laboratory

Ed Vineyard Oak Ridge National Laboratory

David Wood Oak Ridge National Laboratory
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This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Appendix C. 

Detailed Notes From Breakout Sessions

Breakout 1: QC Challenges

Table C-1. Notes from Breakout 1A—SETO 

QC Challenges 

Summary:

• Algorithm/automation development (3)

• Sensitivity of sensors/measurement (0)

• Understanding of defects with respect to product performance (Everyone)

• Cost of new technology implementation and return on investment (Everyone) 

o Custom tools/degree of customization

o Challenges to justify cost of QC due to size of market

• Education of customer and qualification of new tools (1)

• How do defects affect the expected reliability over decades of expected lifetime (4)

• Resolution of measurement techniques / field of view (3)

• Speed of QC data acquisition (4)

• Moisture, shunts, shorts, electric activity, modeling cause and effect (1)

• Accuracy of actual techniques / PV defect mapping, location, type (3)

Detailed notes:

• Observation thermography for detection of solar cell shunts, shorts 

• Building-integrated PV:

o Clear photovoltaics on windows—optical defects significant

o Deviation in color, optical flatness, bubbles, voids

o Inspection visually = hard to take large panel and look; circle defects/characterize types 

of defects hard work 

• Way to automate? Current sensors don’t have same sensitivity to optical deviation as human 

eyes

• Divergence of parallel lines—can be detected by human eye

• Photography fails when trying to detect “warble” defects, whereas to the eye it is very apparent

o Can create artificial situation to detect optical distortion—escape quantification

• Need improved sensitivity of sensors, along with algorithms for the sensors, to detect defects

• How much development/understanding to failure modes is needed? “How good is good enough?”

• Quantify size and type and extent—what defects are “relevant”?

o “Fish eyes” vs. “warble” 

 “Fish eyes” are easy to detect and quantify

 Off-axis color—coatings or film (not looking to directly but to the side or against 

different lights)

o How many and what type? What about below vs. above tolerance? 

• How hard is it to develop Pareto chart with main types of defects? 

o Can it be done in software?

o Big difference between number, type, annoyance -> algorithm (assuming defects can be 

detected by sensors)

• Ignore defects that have no relevance to the outcome?

o Different technologies have different requirement with different final product purpose

o “X” defect will do “Y” to the system is not always known for each application

• Cosmetic defects vs. major defects that could kill the system

o Incoming inspection is a high request (for end user)
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 Coatings

 Roll-to-roll Al metal from companies who don’t do a lot of control

 Breakage in material (edge could propagate)

 Glass—TV and computer displays with defects will crack if put in a frame

• In-line approaches? 100% inspection system and edges with glass

• How hard is it go to in-line tools PV systems for QC/metrology?

o Turnkey solution like incoming glass inspections

o Glass industry already has technology

o Specific: develop in-house or customized

o Generic: build on existing industries

o Specific generally harder to implement and develop

o Yield improvement and breakage—important for commercial scale

• Difficulties in new R&D metrology into brand new process/material set/industry?

 Metrology from lab to industry: must be fast, non-contact, low-temp (?)

• Challenges that the customer sees?

o They don’t understand the in-line metrology equipment or how it works

o What happens if we don’t use QC? 

• Provide service instead of tools? Prepay for consulting services to help instruct the users on the 

proper use of the in-line metrology equipment?

o Customers think it is expensive to have engineers on-site; but can they afford not to do 

QC checks?

• Return on investment—consultant to keep QC, but customers don’t see the cost benefit of having 

correct QC/metrology

Table C-2. Notes from Breakout 1B—FCTO 

QC Challenges

What are the current QC techniques being used?

• Optical (human vision, machine vision)

• X-ray to identify voids in ceramics (SOFC)

• High frequency resistance measurements for catalyst layer

• Machine vision for process control (e.g., registration), but human for final part QC

• X-ray diffraction of powders to screen for size

• Physical dimension measurements of supplied parts

• Thickness uniformity (measured by weight) of anode supported cast tapes 

What are current QC challenges?

• Difficult to measure electrochemical properties of SOFC in line (need to bring up to operating 

temperature)

• Membrane: limited pinhole detection; rely on supplier

• Bipolar plate: detecting micro-cracks, measuring nitride (anti-corrosion) layer thickness, degree of 

planarity/flatness

o Leak checking bipolar plate—compress plates, put in water, and pressurize to find 

crack/leak manually

• Electrodes: thickness and catalyst content

• Gaskets and seals: need better understanding of what properties lead to better performing seals

Comments:

• Dimensional metrology is well understood; thickness, height, dimensions can be measured

• Pinhole length scale is not well understood; isn’t clear what size results in failure

• Need to correlate defects to performance loss or degradation

• Need further development of accelerated testing methods for all components
36 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Table C-3. Notes from Breakout 1C—VTO

QC Challenges

Defect types and criticality for battery electrodes:

Defect Source Result Gravity/ 

Frequency 

NonMetrology 

Remedy

Metrology

Metal Mixing 

debris, 

slitting 

debris

Short circuit, 

overheating

Grave/seldom Optical, 

thermography

Coating (pinhole, 

blister, porosity) 

Mixing, 

slurry 

process

Life Medium

Coating thickness Pump, roll 

position

Capacity, 

safety

Low

Material 

agglomerates

Slurry Safety Medium

Moisture Air Safety Low/expensive?

Powder 

homogeneity

Milling

Challenges:

• Measurement challenge on one sided electrodes. Are we measuring something that matters??

• Scrap material: we may need to be marking scrap material; at this point no one is doing this yet. 

We scrap a lot of material due to false positives

• Defects (see summary table above)

• Homogeneity: particle size, distribution, porosity, thickness

• Performance or quality of battery: has this been mapped back to defects? 

• Slow formation cycles

• Battery lifetime

• Safety

• Clean room environments

Questions for thought:

• How much can we learn from other technologies?

o Are there similarities with the AMO side? Are we using the same techniques?

• Should/can we replace beta gauge with something cheaper?

• Is optical a better way to go as this is a more controlled environment?

• How do you represent quality?

• Do we have a tool that can measure porosity or large area?
37 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Table C-4. Notes from Breakout 1D—BTO 

QC Challenges

• “Buildings” is a very large topic, with many components

• Material selection in windows is an important part of QC

o Good at sale of product vs. X years of use (e.g., window gas)

o What QC is needed with new materials?

• Material choices are often made by manufacturers by spot cost of material

• Flammable refrigerants = smaller heat exchangers in HVAC equipment = different risks

• Compressors: oil-less have tighter tolerances, new testing methods and thresholds are needed

• Everything fails, eventually

• How can materials be tested without destroying them?

• What accelerated aging tests are appropriate?

• Embedded sensors provide real-time data

o Treat building like a system

• Quality of certifications matter

• Environmental and public pressures on manufacturers to change a material and/or product

• Risk mitigation for manufacturers is very important

• Construction is often a low-tech exercise at erection of structure

• New products require new regulations

Breakout 2: Synergies

Table C-5. Notes from Breakout 2A

Synergies 

• Battery electrodes:

o Electrode deposition is similar to other coating applications

o In-line X-ray measurement

 X-ray fluorescence (to measure areal loading) is utilized by a couple of fuel cell 

companies

 Not yet established as an in-line measurement for batteries; should be 

translatable

o Off-line X-ray

 Primary Li-ion batteries X-ray to measure electrodes—make adjustment to the 

foil on the spot?

 Secondary to the Li-ion people, are not doing that yet

 Li and cobalt or cobalt-oxides  measured CoO areal weight

 Transition metal areal weight by XRF

• PV measures electrical characteristic of a cell

o Are there similarities in electronic or electrochemical measurements for fuel cell or battery 

materials?

o For PV, electrical measurements are made of actual device voltage once connections are 

made on cell

 P-n junction is deposited during coating

o For fuel cell and battery, no ex situ voltage exists, so want to make measurements of 

electrical properties, not actual voltage

o Look at electronic characteristics (and properties) of silicon wafers by photoluminescence 

(or some other method)

 Thin films need junction to measure voltage

 Measure conductivity of substrate; lateral sheet resistance

 Radio wave? Electronic impedance? Capacitance? Eddy current? Excitation for 
38 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

battery or fuel cell

• Crystalline materials—determined by grain properties

• Non-contact measurements—some have constraints on thickness

o Spot fusing

o Electronic properties/permeability

o Expensive transducers in the past

o Microwave deflection? Look at absorption and transmission then back out the dielectric 

current?

• Some defects accelerate failure (i.e., in fuel cells)

• Maybe a better format for identifying synergies would be to have an exchange of technical 

methodology of metrology examples. Maybe focus on smaller technical meetings (or webinars) to 

discuss methodology and how one new device/process could be adopted by others either in their 

field or across technologies

• Cross-cutting FOAs? Who can justify the need for DOE to engage in these cross-cutting 

activities?

• Theme of national lab summit or showcase 

o For wider participation try webinars or national conference

o Have a QC side-event at Annual Merit Reviews?

o Solar office incubators/start-ups provide a 1-minute elevator pitch at a webinar with 

venture capitalists as well. Have a list of attendees for cheap, quick networking

o Virtual showcase

o Learn high-level what other programs have done, mistakes made 

• Low-cost IR camera techniques

o Other uses?

o Resolution?

o Similar spatial resolution or more expensive

o No built-in screens could be a detraction of the cheaper cameras. Depends on the 

particular needs

• Overlap measure of texture? Scattering? Could this PV technique be developed with fuel cells, 

batteries?

o What would the process control outputs look like?

• Desired outcomes:

o Collaboration

o Transfer technologies to industry

• Why aren’t manufacturers using in-line QC techniques? QC techniques are becoming useful but 

manufacturers say volumes are not high enough yet to justify the time or cost of testing and 

implementing them

• Manufacturer specifications versus in-line checks. Who is responsible for making QC checks? 

Some rely on manufacturers to provide good materials

• Good area for national labs to collaborate and work on these issues. They can address issues 

faced by manufacturers before manufacturers need to put processes in place

o Some of these technologies have not been scaled up yet. Manufacturers have not been 

able to look at process development, and this is where labs can step in

• Manufacturing customization—make same tool to work with fuel cells, PV, etc.?

o Thickness, surface inspection

o But, adds cost

• University challenge of staying relevant. Struggle to work with industry due to intellectual property

constraints

• Topography—important texturing step in PV

o Morphology: measure for fuel cells and PV; look into battery electrodes?

• Thickness and porosity 

o Similar thickness needs across technology platforms

o But, PV and fuel cells/batteries have different thicknesses (nanometer versus 

micrometer)

• Relationship between dielectric properties and porosity? 
39 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

o Manufacturer specs can provide some information 

o Measure transport limits

o Not a real study of pore size distribution

o Coating for battery not the same as for glass

• How and when in the process should these measurements be taken?

• Conductive layers/in-plane resistance (but not a specific layer to measure)

• Pinholes in batteries and fuel cells

o In the coating and separator

o Tier 1—pinholes in the battery electrode is of interest

o Tier 2—battery separator manufacturer should take care of their pinholes

o Fuel cells with pinholes in membranes—shorts can occur

• For batteries, transition metal areal weights are measurable but total metal areal weights are 

difficult to measure

• For PV, conductivity is a critical as soon as p-n junction is formed

• Idea for DOE to provide a forum for researchers to see others’ monthly reports

• Maybe we can carve out a session at this year’s AMR? What about doing a national lab webinar 

series?

• Each office needs to better understand the impact of defects on performance and durability to 

correlate those defects to not only reduced scrap/higher yield, but also to some cost benefit

Table C-6. Notes from Breakout 2B

Synergies 

• QC methods need to be non-invasive, non-contact, fast

• Performance correlation is not clear

o Does defect affect performance later or result in immediate problem?

• Common problems are difficult to define due to different applications

• Thin films, coatings—common mechanical problems

• Software—analysis of results, interface, and algorithms for classification

• Cost of defect detection has to be lower than cost of defect—perceived return on investment

• In some cases, techniques are available but do not know how to apply it to the different 

applications

Defects which cannot be measured at this time:

• Physical vapor deposition of glass onto plastics—10-5 per day moisture permeation needed—

defects on the scale of 10 nm cannot be measured

o Application maybe of 5 micro-inch cast to such problems? Scale?

• Cost might inhibit existing technique to be used and applied

Commonality between applications:

• Pinholes, micro cracks

o Might have different size depending on application

• Compositional homogeneity

• Reliability

• Accuracy, false positive avoidance

• Software

o Maturity at which software gets implemented varies a lot

• Process control to reduce need for metrology—understand impact

o Statistical quality control is required to perform metrology effectively

• Where should we focus our thought? 0-5 years of horizon for bringing technology to market or 

changing application for technology
40 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Table C-7. Notes from Breakout 2C

Synergies 

• Although there are synergies across the technologies, they are application specific. For instance 

a type of defect might be catastrophic to one technology, but not to another

• Defect examples: pinholes, thickness, X-ray fluorescence, metal fragments, sheet resistance

• Summary of synergies:

o Materials need to work together for long term life

o Quality of deposit, registration

o Techniques for leakage and pinholes

o Thickness

o Not enough understanding of long term aging effects at this time for products

o Current technologies need to be better to be able to use across technologies

o Defects that affect lifespan are different than defects that affect whether it is usable at all

• Defect at point of manufacturing important, but defect shortly thereafter is more important for 

environmental impact

o Testing currently is to put into field and see what happens

• Defects are a matter of scale among the technologies

o A pinhole may be bad, but may not be a killer defect. For example, a pinhole is limited in 

how it will affect solar technologies; for battery it could kill the entire battery

• Some defects can be detected by the eye, but not a camera

o Examples would be optical flatness and off axis color

o Inspection systems that approximate the acuity of human vision system would probably 

solve problems in the industry across all technologies

• How do you measure the quality of white light, i.e. how well a light source used for PV testing 

mimics the sun in terms of spectrum, spatial uniformity at the device-under-test, and 

reproducibility? 

• Need for DOE support of metrology development

Breakout 3: Remaining R&D Needs and Recommendations 

Table C-8. Notes from Breakout 3A

Remaining R&D Needs and Recommendations

R&D needs for QC:

• Are there any solutions to address the issue with pinholes/defects that do not seem to be an 

issue at the time the device is manufactured but appear during operation? 

• Idea that a lot, if not all, structures are multi-layer structures (thin films, membranes, coatings): is 

there a need to evaluate layer-to-layer binding/adhesion?

o Questions about delamination and discontinuations in the bond

o Interface states affected by the bonding used

o Interfacial bonding is very important for many technologies

o Delamination of contacts is an issue

o In fuel cells, electrode-to-electrolyte adhesion is very important

• Delamination—sometimes a manufacturing issue, but often happens during operation

• Batteries (Li-ion) and fuel cells

o Adhesion is important when putting down electrodes

o Ceramic to metal joints can be unstable under load in SOFC

o Binder (polymer) to metal substrate not easy to accomplish; high contact resistance and 

ohmic losses

o Polymer electrolyte membrane (PEM) fuel cells have same polymer in membrane and 

catalyst layer so adhesion during fabrication is not as much of an issue, although 
41 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

delamination can occur as a result of operation

• Currently no good way to do in-line testing for delamination

o Destructive tests or energies of adhesion/contact angle analyses

• Search for delaminations by acoustic tests? (not roll-to-roll)

o Thickness limitations with ultrasonics?

o 80 microns for silicon wafers

o Must use the appropriate frequency: higher frequency for thinner materials

• Electronic technique (mm wave energies)—quality of the interface

o Tune frequency to thickness?

o Each sample has its own resonance curve; adhesion defects will show modified 

resonance

• Interface—electro-migration happens during operation then have to dissect part to look for 

defects

• Voids are easier to detect than bond strength, but would like to have both voids and strength

o Should do cost benefit analysis of doing both

• Polycrystalline coatings

o Adhesion of crystals

o Coating grain size needs to be consistent when using multiple coatings

o Grain size mismatch could lead to void/defects and granularity

• Previous development of in-process measurement that uses high frequency impedance for 

lamination quality of PEM cell

Questions on next steps: 

• What will DOE do with these ideas?

o Support for cross-office activities

o Hard to fund in an AOP-funded manner; brainstorm ways to work together

o Cross-cutting FOAs? Make teaming necessary?

o What if $25 million cross-cut FOA in future? Require part two of workshops with other 

planning steps to add more technical principal investigator presentations

o Europe labs get funding with large collaborative scopes. Find lessons-learned from 

Europe that could be applied in the United States 

• SBIR program focuses on some of these issues.

o SBIR ensures buy-in from manufacturers and tech transfer to industry 

• How to evaluate cost benefit of QC?

o Use manufacturing cost analysis? Get QC into models

o Yield numbers not provided by companies

o Use models such as the ones produced by DTI (for fuel cells)?

o Argonne collects data on Li-ion batteries (VTO research funds)

o Can use competitiveness analyses such as recent NREL work for solar PV?

o What is the cost of not having QC?

 Real processes never have 100% yield, but the manufacturers never give out the 

exact yield—business sensitive

 Example of fuel cell stack yield effect on stack cost: if QC measures are not 

taken, the % of bad product increases costs

• Example of thermography/IR cameras resulting in record dollar savings in power plants

o Costs to show return on investment of having thermography inspection

o Leads to using same cameras for other applications that help reduce the cost of the 

manufacturing plant

o Thermography now required for electric plants (save lives and money)

• Nanotech center in New York has a pilot fabrication (FAB) lab for data collection. Set up more of 

these fab labs to investigate the use of QC/metrology in manufacturing setting

• Intellectual property issues inhibit collaborations and effective teaming
42 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Table C-9. Notes from Breakout 3B

Remaining R&D Needs and Recommendations

R&D needs for QC:

• Intelligent process control needs

o Example: CIGS—DARPA, consortium with nine companies, vapor phase manufacturing, 

how to control four element deposition correctly

o Run machines dynamically for 30 or 40 hours or more

o CIGS roadmap from Sematech

• Offline techniques might be available—how to bring them online

• Understand what needs to be measured

o Solar might have an understanding; batteries are lagging

o Difference in needs between surface and bulk

o Classification for focusing effort needed

• Six sigma—what are the things we can measure and how well do we need to measure them?

• BTO has less focus on QC or metrology as a subject even though it might be used or needed for 

a product

o Focus is on final product

o Webinars might be good to keep community informed

• Catalogues needed of QC techniques available

• Translation of laboratory techniques to production sites difficult—understanding lacking on the 

laboratory side about manufacturing needs 

• Technology driven partnerships might be inhibited by competitive considerations in expert groups 

and partnerships

Focus of program needs to be on manufacturer:

• Manufacturer does not want metrology on their line

• Only accepted if there is an impact on their productivity and bottom line (i.e., if manufacturer has 

a problem and it hurts) 

Needs that are not being met by commercially available technology:

• Might be available but too expensive

• Example: time-resolved photoluminescence

• Current techniques signal problem but do not give guidance for correction

Needs to be addressed by EERE:

• How to improve collaboration with manufacturer? Understand manufacturers’ challenges in a 

competitive environment?

• Correlation of inspection to process control via classification through data analysis software

General considerations:

• Expertise in manufacturing is critically low—manufacturing R&D and scientists are not with 

companies anymore

• Manufacturing brain drain—switch to services organization

• Problem of profit center profitability from day one in United States vs. global long term vision in 

Eastern Asia

• Loss of workers—everybody wants to be a manager and accountant
43 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Table C-10. Notes from Breakout 3C

Remaining R&D Needs and Recommendations

R&D needs for QC:

• Vision systems that replicate the processing ability of the human brain and eye 

o The human eye is a great screening tool, but people get tired and make mistakes 

o Ability to quickly differentiate between features like the human eye can, but by camera

o Hardware improvements and/or software improvements will be needed to achieve this

o It would be helpful for the vision system to detect things smaller than the diffraction limit 

of what the human eye can detect 

• The ability to process and detect defects over large scales (looking at small things over large 

areas or detecting one defect over a large area)

o There is no current method to look at physical features in intermediate scales over large 

surface areas

o We have good optical techniques (e.g., microscopic) that work at short enough 

wavelengths for small areas, but it is very hard to measure defects (around 0.5 micron) 

over square meters of materials 

• Create a large database and data mining effort from which the data can be analyzed to determine 

what is statistically different 

o Use big data mining techniques to accumulate a lot of data and help apply this to the 

problem 

o Oversample and then try to look back at the data (see why samples were degrading or 

further analysis... etc.). 

o Go back in time and see what is statistically significant. Large data set may show trends, 

but we need the data set first

o Three problems (initial data collection, storage of data, and going back to look at the 

data)

• Define what a real versus perceived defect is 

o What is a variation vs. an actual defect? 

o Try to identify what the actual characteristics are of a defect 

o Need measurement techniques that can identify defects that are relevant to the specific 

application 

o We throw out a lot of material from being too conservative with perceived defects 

• Process integration issues with equipment and the need for standardization (manufacturers need 

to be working hand in hand with the QC vendors) 

o Every application of sensors is different from the equipment vendor perspective 

o Would be good to have standardization. A lot of custom applications for standard 

equipment

o Generally use offline analysis to show issues with equipment (labs, etc.)

o A lot of issues come up with data collection and control systems 

• Generate a table that summarizes QC techniques and their capabilities (defect size, line speeds, 

etc.) 

o Make a table for renewable energy technologies for defect definition, irregularities, how to 

detect them and different synergies 

o A table showing QC techniques used and how they are applied and then have equipment 

vendors and others come in and fill gaps for areas of QC that aren’t well defined

o A speed-dating type activity where QC equipment vendors could help identify ways to 

look at the defects identified by manufacturers 

• More customizable products = less tolerances

o Continue to improve yield by reducing cost by building in tolerance variations 

o Need a good feel for what variables matter 

o Issues surrounding poor build quality products. Whether to ramp up QC and inspection or 

get liability insurance (due to bad design) 

Questions on next steps:
44 

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

• What could DOE do to help?

o Metrology webinar series under the AMO umbrella so that it can cross multiple 

technologies

 If the topic is specific to “solar” as opposed to “metrology” then people may not 

tune in if they are in the fuel cell industry

 Make sure to add contact information for the presenter and organization for 

people to follow up with after the webinar 

o DOE could get lots of end users at meetings where QC options are presented 

o Finding a way of bringing people that “cross pollinate” across multiple industries to attend 

meetings and workshops

o Meetings to minimize travel. Hold events at well attended events. Invite people to 

manufacturing meetings or conventions 

o More breakout sessions 

• Improve buy-in from and tech transfer to industry

o Taking technology from the laboratories and demonstrating it at real companies for a brief 

period

o Helping companies identify and then resolve issues; convince companies of the payoff of 

the technology

o Could make companies hesitant because of QC issues that get sampled—manufacturers

do not necessarily want their defects or manufacturing issues to be known by the outside